The network of included trials in GINA step 3&4. ICS = Inhaled Corticosteroids; LABA = Long–acting β2-adrenoceptor agonists; SR= Sustained release. The arrows represent the direct comparisons found in the included RCTs, including the number of RCTs and total number of participants. Except for SR theophylline as add-on to step 3, all treatments are directly or indirectly connected to each other. An example of an indirect comparison replacing a non-existent comparison is step 3A to 4A, through 3A to 3B, and 3B to 4A.